JP2002303883A - Semi-transmissive active element board and method for manufacturing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semi-transmissive active array board and a method for manufacturing it, permitting to maintain high reflection efficiency without damaging production efficiency. SOLUTION: As an active element array board constituting a liquid crystal display device, a pixel part is provided with a diffuse reflecting area and a transmissive area by making a 1st reflecting layer 13 formed on the same layer as gate electrodes and a rugged layer 17 formed on the same layer as an α-Si film 15 and an ohmic contact layer 15 cross a 2nd reflecting layer 20 formed on the same layer as a source electrode 18 and a drain electrode 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an active element array substrate constituting a liquid crystal display device used for an information processing terminal or a video device and a method of manufacturing the same. In particular, the present invention relates to a semi-transmissive active element array substrate that performs display by reflecting incident light and display by transmitting backlight, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A transflective liquid crystal display device displays an image while reflecting an external light incident from a front side of the display device on a transflective plate in a bright environment where natural light, indoor lighting, or the like is present. In a dark environment where there is no natural light or indoor lighting, display is performed by transmitting the backlight from the back side, so that the display quality is constant regardless of the surrounding environment. Is characterized in that it can be maintained.

As a semi-transmissive active element array substrate, for example, a structure disclosed in Japanese Patent Application Laid-Open No. H11-183892 is generally used. FIG. 14 shows a front view of such a conventional transflective active element array substrate.

In FIG. 14, reference numeral 12 denotes a gate electrode;
5 denotes an α-Si film, 18 denotes a source electrode, 19 denotes a drain electrode, 20 denotes a second reflective layer, and 23 denotes a transparent pixel electrode.

As shown in FIG. 14, by providing the second reflective layer 20 on a part of the transparent pixel electrode 23, in an environment where the surroundings are bright, external light is transmitted to the second reflective layer 20.
In the environment where the surroundings are dark, the second reflection layer 2 of the transparent pixel electrode portion 23
Display is performed by transmitting backlight from a portion where 0 does not exist.

[0006]

However, in the conventional transflective type active element array substrate as described above, when the display is performed by reflection of external light by the second reflection layer 20, the second reflection layer Since the reflection layer 20 has a large number of flat portions, the reflected light itself contains many specular reflection components, and thus it is difficult to obtain a desired diffuse reflection performance.

In order to solve such a problem, it is conceivable to use a semi-transmissive reflector on the back surface of the semi-transmissive active element array substrate. However, this increases the manufacturing cost of the liquid crystal display device itself and reduces the cost. It is difficult to provide a liquid crystal display device.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a semi-transmissive active element array substrate capable of maintaining high reflection efficiency without impairing production efficiency, and a method of manufacturing the same.

[0009]

In order to achieve the above object, a semi-transmissive active element array substrate according to the present invention drives a liquid crystal sandwiched between two substrates through a plurality of pixel electrodes. A driving semi-transmissive active element array substrate in a liquid crystal display device that displays an image by using a gate electrode, a gate insulating film, an α-Si film, an ohmic contact layer, a source electrode, and a drain electrode. A first reflective layer formed on the same layer as the gate electrode, a concave-convex layer formed on the same layer as the α-Si film and the ohmic contact layer, a source electrode and a drain electrode, A semi-transmissive layer having a diffuse reflection area and a transmission area formed by overlapping a second reflection layer formed on the same layer is formed. It is characterized by having been done.

[0010] With such a structure, the desired diffuse reflection performance can be easily ensured by forming the concave and convex portions on the reflection layer, and a transflective active element array substrate having high reflection efficiency as a whole can be obtained. Becomes possible.

Further, in the semi-transmissive active element array substrate according to the present invention, the gate electrode, the first reflection layer, the source electrode, the drain electrode, and the second reflection layer each include C
It is desirable to be any of r, Al, Al alloy, Ag, and Ag alloy.

In order to achieve the above object, a method of manufacturing a semi-transmissive active element array substrate according to the present invention provides an image by driving a liquid crystal sandwiched between two substrates through a plurality of pixel electrodes. A method of manufacturing a driving transflective active element array substrate in a liquid crystal display device for displaying, wherein a gate electrode layer and a first reflective layer are formed by forming a gate electrode layer on one substrate and then etching the gate electrode layer. Forming, forming a gate insulating film, an α-Si film, and an ohmic contact layer on the gate electrode and the first reflective layer, and then etching to form a concavo-convex layer; Forming a source / drain electrode layer and a second reflective layer by etching after forming a source / drain electrode layer on the uneven layer; A step of forming a contact hole by etching after forming an insulating film layer on the in-electrode and the second reflective layer, or a photolithographic method after forming a photosensitive organic insulating film thereon. And forming at least one of a step of forming a contact hole and a step of forming a transparent pixel electrode on the contact hole by etching after forming the transparent electrode layer on the contact hole.

[0013] With this configuration, since the concave and convex portions are formed on the reflective layer, a desired diffuse reflection performance can be easily secured, and it is not necessary to use a transflective reflector on the back surface of the substrate. It is possible to maintain high reflection efficiency without impairing production efficiency.

Further, according to the method of manufacturing a semi-transmissive active element array substrate according to the present invention, the gate electrode, the first reflective layer, the source electrode, the drain electrode, and the second reflective layer are
Desirably, each of them is any of Cr, Al, an Al alloy, Ag, and an Ag alloy.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A transflective active element array substrate according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a semi-transmissive active element array substrate according to the present embodiment.
7 are cross-sectional views showing the steps of manufacturing the semi-transmissive active element array substrate shown in FIG. FIG.
13 to 13 are process-by-step front views showing the steps of manufacturing the transflective active element array substrate shown in FIG.

Hereinafter, a manufacturing process of the semi-transmissive active element array substrate according to the present embodiment will be described with reference to FIGS. First, as shown in FIGS. 2 and 8, a 200-nm-thick Al film is formed on a glass substrate 11 by a sputtering method, and then a gate electrode 12 and a first reflective layer 13 are formed by etching.

Next, as shown in FIGS. 3 and 9, a plasma enhanced chemical vapor deposition (hereinafter referred to as "p-CVD") method.
As a result, the gate insulating film (SiNx) 14, the α-Si film, and the n-type α-Si film
After forming a film having a thickness of nm, the α-Si film 15, the ohmic contact layer 16, and the concavo-convex layer 17 which are to be channel layers of the active element are formed by etching.

Then, as shown in FIGS. 4 and 10, after forming an Al film having a thickness of 200 nm by a sputtering method, a source electrode 18, a drain electrode 19 and a second reflection layer 20 are formed by etching. I do.

Next, as shown in FIGS. 5 and 11, an insulating film (SiNx) 21 having a thickness of 200 nm is formed by a p-CVD method, and then a contact hole is formed by etching.

Then, as shown in FIGS. 6 and 12, an organic insulating film 2 having a thickness of 3 μm is formed using an acrylic photosensitive resin.
2 and a contact hole is formed by photolithography.

Next, as shown in FIGS. 7 and 13, an ITO film having a thickness of 150 nm is formed by a sputtering method, and the ITO film is connected to the drain electrode 19 and the second reflection film 20 through the contact hole. By performing patterning as described above, the transparent pixel electrode 23 is formed, and the active element array substrate in the transflective liquid crystal display device is completed.

According to the thus-obtained semi-transmissive active element array substrate according to the present embodiment, since the uneven layer is formed on the reflective layer, the reflected light itself contains a regular reflection component. As the desired diffuse reflection performance can be obtained, the diffuse reflection efficiency is increased, and the production efficiency is not impaired because a new production process is not added as compared with the conventional production process.

[0023]

As described above, according to the transflective active element array substrate and the method of manufacturing the same according to the present invention, uneven portions can be formed in the reflective layer without increasing the number of manufacturing steps. As a result, it is possible to obtain a transflective active element array substrate having a high reflection efficiency without impairing the production efficiency and a method for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a transflective active element array substrate according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a semi-transmissive active element array substrate according to an embodiment of the present invention in each step.

FIG. 3 is a cross-sectional view of the semi-transmissive active element array substrate according to the embodiment of the present invention, which is obtained by different processes;

FIG. 4 is a cross-sectional view of a semi-transmissive active element array substrate according to an embodiment of the present invention in each step.

FIG. 5 is a cross-sectional view of the semi-transmissive active element array substrate according to the embodiment of the present invention in each step.

FIG. 6 is a cross-sectional view of the semi-transmissive active element array substrate according to the embodiment of the present invention, for each process.

FIG. 7 is a cross-sectional view of the semi-transmissive active element array substrate according to the embodiment of the present invention in each step.

FIG. 8 is a front view of each step of the semi-transmissive active element array substrate according to the embodiment of the present invention.

FIG. 9 is a front view of each step of the transflective active element array substrate according to the embodiment of the present invention.

FIG. 10 is a front view of each step of the semi-transmissive active element array substrate according to the embodiment of the present invention.

FIG. 11 is a front view of each step of the semi-transmissive active element array substrate according to the embodiment of the present invention.

FIG. 12 is a front view of each step of the transflective active element array substrate according to the embodiment of the present invention.

FIG. 13 is a step-by-step front view of a semi-transmissive active element array substrate according to an embodiment of the present invention.

FIG. 14 is a front view of a conventional transflective active element array substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Substrate 12 Gate electrode 13 First reflective layer 14 Gate insulating film 15 α-Si film 16 Ohmic contact layer 17 Uneven layer 18 Source electrode 19 Drain electrode 20 Second reflective layer 21 Organic insulating film 22 Transparent pixel electrode

Continued on the front page (72) Inventor Yoshinari Sakurai 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 2H092 JA26 JA29 JA38 JA42 JB07 JB13 JB23 JB32 JB38 JB57 KA05 KB24 MA08 MA13 MA17 MA27 MA35 MA37 NA27 NA29 PA12 5C094 AA11 AA43 AA44 AA48 BA03 BA43 CA19 DA13 DB01 DB04 EA04 EA05 EB02 FB02 FB02

Claims (4)

[Claims] 1. A driving semi-transmissive active element array substrate in a liquid crystal display device for displaying an image by driving a liquid crystal sandwiched between two substrates through a plurality of pixel electrodes, comprising: a gate; A first reflective layer formed on the same layer as the gate electrode, wherein a channel portion in the active element is formed by the electrode, the gate insulating film, the α-Si film, the ohmic contact layer, the source electrode, and the drain electrode; By stacking an uneven layer formed on the same layer as the α-Si film and the ohmic contact layer and a second reflective layer formed on the same layer as the source electrode and the drain electrode A transflective active element array substrate, wherein a transflective layer having a diffuse reflection area and a transmissive area to be formed is formed. 2. The gate electrode, the first reflection layer, the source electrode, the drain electrode, and the second reflection layer are each made of one of Cr, Al, an Al alloy, Ag, and an Ag alloy. The transflective active element array substrate according to claim 1. 3. A method for manufacturing a driving transflective active element array substrate in a liquid crystal display device for displaying an image by driving a liquid crystal sandwiched between two substrates through a plurality of pixel electrodes. Forming a gate electrode layer on one of the substrates and then etching to form a gate electrode and a first reflective layer; and forming a gate on the gate electrode and the first reflective layer. A step of forming an uneven layer by forming an insulating film, an α-Si film, and an ohmic contact layer and then etching; and forming and etching a source / drain electrode layer on the uneven layer. Forming a source electrode, a drain electrode, and a second reflective layer, and forming an insulating film layer on the source electrode, the drain electrode, and the second reflective layer. Forming at least one of a step of forming a contact hole, or a step of forming a contact hole by photolithography after forming a photosensitive organic insulating film thereon, And forming a transparent pixel electrode by etching after forming a transparent electrode layer on the substrate. 4. The gate electrode, the first reflection layer, the source electrode, the drain electrode, and the second reflection layer are each made of one of Cr, Al, an Al alloy, Ag, and an Ag alloy. A method for manufacturing a semi-transmissive active element array substrate according to claim 3.